The davy clan seems to know about like, Imu and shit, lol. Why would they use the government name for the Nika fruit? Even people like Vegapunk just found old books that has the name of the fruit in it. It´s just absolutely pointless to establish it as a plot point that Rocks doesn´t know about Nika when Loki asks him about it, and that Rocks was also looking for the Nika fruit. Clearly he was after a different fruit(with the Yami pretty much being guranteed, imo)
Why would we assume this?